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NXT Robot

The goal of this project is to connect an old Android smartphone (e.g. HTC Magic) to a Lego NXT robot, in order to get a global available WIFI GPRS UMTS camera robot.

The easiest way to monitor your household from anywhere in the world is to connect an old Android smartphone with a mobile NXT robot. A NXT robot represents a cheap and simple to handle microcontroller device in combination with two servos, that allow to build a flexible mobile platform. On top of this mobile robot we place the Android smartphone. The Android smartphone acts as high-level controller that receives commands over the Internet and transmits these commands to the NXT controller over a Bluetooth connection.

To offer the highest flexibility of control, we implement a tiny HTTP server (by using nanohttpd library) that runs as an Android background service. This HTTP server waits for incoming requests and serves a single HTML5 robot control Web page. This page shows the actual camera image, taken from the Android device, as well as basic control buttons for moving the NXT robot around:

I designed and built a quite simple mobile Lego robot that holds plenty of space on its back in order to carry a long lasting 7.2 V battery. This battery provides the power for the NXT robot as well as for the HTC magic smartphone (via mini USB plug and a 5V voltage converter).

Following HTML5 page shows the basic controller interface the NXT robot is serving directly through its nanohttpd HTTP server: